package com.itheima.reggie.controller;

import com.itheima.reggie.common.R;
import com.itheima.reggie.entity.Employee;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.UUID;


/**
 * 文件上传和下载
 */
@Slf4j
@RequestMapping("/common")
@RestController
public class CommonController {
    @Value("${reggie.path}")
    private String basePath;
    /**
     * 文件上传
     * @param file
     * @return
     */
    @PostMapping("/upload")
    public R upload(MultipartFile file){
        //file是一个临时文件，需要转存到指定位置，否则本次请求完成后临时文件会删除
        log.info(file.toString());
        //原始文件名
        String filename = file.getOriginalFilename();
        String substring = filename.substring(filename.lastIndexOf("."));//截取最后一位小数点后面得数据
        //使用UUID重新生成文件名，防止文件名称重复造成文件覆盖
        String fileName = UUID.randomUUID().toString() + substring;
        //创建一个目录对象
        File file1 = new File(basePath);
        //判断当前目录是否存在
        if (!file1.exists()){
            //目录不存在，需要创建
            file1.mkdir();
        }
        try {
            //将临时文件转存到指定位置
            file.transferTo(new File(basePath+fileName));
        } catch (IOException e) {
            e.printStackTrace();
        }
        return R.success(fileName);
    }

/**
 * 文件下载
 * @param name
 * @param response
 */
@GetMapping("/download")
public R download (String name , HttpServletResponse response) throws IOException {
    //输入流，通过输入流读取文件内容
    FileInputStream inputStream = new FileInputStream(basePath+name);
    //输出流，通过输出流将文件写回浏览器
    ServletOutputStream outputStream = response.getOutputStream();
    response.setContentType("image/jpeg");

    byte[] bytes = new byte[1024];
    int len =0;
    while ((len=inputStream.read(bytes))!=-1){
        outputStream.write(bytes,0,len);
        outputStream.flush();
    }
    //关闭资源
    outputStream.close();
    inputStream.close();
    return null;
}

}
